[Cyruz]

did anyone ever do a comparison or dyno the difference between catted and catless on the same car or same set us on the same dyno? if the gains are that dramatic, maybe id sneak the catless the wife and kid.

[blisstik]

Catless gains are about 5-10 whp depending on your car, mods and dyno. I've seen graphs that show as little as 5whp difference on power and torque.

Originally Posted by Cyruz

did anyone ever do a comparison or dyno the difference between catted and catless on the same car or same set us on the same dyno? if the gains are that dramatic, maybe id sneak the catless the wife and kid.

[s.myrr]

BMS has the newer v3 adjustable o2 sims... hopefully those are working out as well for those with newer software. Anyone using these on a 2010?

[boom]

I had the carted cp-e and they failed after a couple of weeks. I rode around with cel for months as they were researching a new cat substrate material that could take the heat. I'm happy to report no codes whatsoever after 1000+ miles since installing their new catted DPs.
The hp difference is about 5 who less with cats.

[blisstik]

Is this without any sims? So no CELs on "newer" cp-e catted downpipes? When did you buy your "newer" dps? Do you WOT a lot?

Originally Posted by boom

I had the carted cp-e and they failed after a couple of weeks. I rode around with cel for months as they were researching a new cat substrate material that could take the heat. I'm happy to report no codes whatsoever after 1000+ miles since installing their new catted DPs.
The hp difference is about 5 who less with cats.

[cn555ic]

If you going to change out the DPs, best go with catless for the performance gains and leave the secondary cats in place...Going catted DPs upgrade is kind of a waste if you ask me..but my opinion

[Syndicategt]

Originally Posted by cn555ic

If you going to change out the DPs, best go with catless for the performance gains and leave the secondary cats in place...Going catted DPs upgrade is kind of a waste if you ask me..but my opinion

Not a waste when you live in states with very very strict emissions. Having 4 "available" when going to smog makes all the better. Ok they might cost more, and you lose at most 5-7 hp, but it's worth it IMO.

[Cyruz]

already lost the secondary cats and they got trashed.

[ar design]

To be clear, we DO still offer the original style downpipe. We now offer the OPTION of adding the HJS cats - which admittedly are obscenely expensive - but that is something that is out of our hands

[Hyper psi-atic]

No-one has cp-e catless? Was trying to determine between them and AR for my DP's, since cp-e's shop is not too far from me and I could go to them for any issues. But I also have only heard good things about AR DP's so I'm guessing they are the ay to go.

[uberschnell]

Has anyone passed an actual "required" smog check at a Test-only station yet?

As far as I can tell no 335 in California should have been required to smog check yet.

"If your vehicle is six years old or newer, you will are charged an annual smog abatement fee when you register your vehicle, rather than being required to provide smog certification.

Exceptions
The six-year-or-newer rule doesn't apply to nonresident and custom-built cars made since 1976. Those vehicles require smog certification. If you have a custom or specially constructed car, however, you might need a different type of smog certification.

Top Title Transfer and Smog Requirements
When you sell a vehicle that is four or fewer model years old, a smog certificate will not be required in order to transfer the title"

[Alpina_B3_Lux]

Originally Posted by ar design

To be clear, we DO still offer the original style downpipe. We now offer the OPTION of adding the HJS cats - which admittedly are obscenely expensive - but that is something that is out of our hands

LOL

I got HJS secondary replacement cats in my car right now. 700 EUR per piece, i.e. 1400 EUR for a whole set = around 1900 USD only for the cats. But they ARE of really excellent quality.

Alpina_B3_Lux

P.S. I had the ar design catted dps (with the Magnaflow cats) in my car for about a year without any problems. They fit spot on.

[ar design]

Originally Posted by Alpina_B3_Lux

LOL

I got HJS secondary replacement cats in my car right now. 700 EUR per piece, i.e. 1400 EUR for a whole set = around 1900 USD only for the cats. But they ARE of really excellent quality.

Alpina_B3_Lux

P.S. I had the ar design catted dps (with the Magnaflow cats) in my car for about a year without any problems. They fit spot on.

[rismo]

I got HJS secondary replacement cats in my car right now. 700 EUR per piece, i.e. 1400 EUR for a whole set = around 1900 USD only for the cats. But they ARE of really excellent quality.

Alpina,

What would you think about combining the HJS with the Turbo Dynamics turbo upgrade stage 1 or 2?

Or would they be to restrictive and would catless dp's be recommended?

Our local emmision regulations are quite strict and the first emmision check starts after the 2th year the car has been on the road...

[Alpina_B3_Lux]

Originally Posted by rismo123

Alpina,

What would you think about combining the HJS with the Turbo Dynamics turbo upgrade stage 1 or 2?

Or would they be to restrictive and would catless dp's be recommended?

Our local emmision regulations are quite strict and the first emmision check starts after the 2th year the car has been on the road...

You can combine the Turbo Dynamics upgrade with any other configuration you choose - if you need to pass emission testing, I would leave high-flow cats in the downpipes. However, if you have a more or less catless system you can run higher boost on the upgraded turbos without fear of exhaust temperatures rising too high and damaging your stock cats.

Alpina_B3_Lux

[boom]

There will become a point when no cat will work as you move to higher and higher power levels. At least, not in the DP. You may be able to put larger HFCs in the exhaust and move the narrow band sensors out past them.

[Imperator]

Bumping an old topic instead of creating a new thread. I'm contemplating HFC downpipes over catless as I prefer to install downpipes just once and forget about it, even when selling the car.

I have a 2010 with the latest DME revision so I'm curious if CP-E or AR's catted downpipes will lead to catalytic efficiency codes once installed, with or without a tune.

Eventually, I plan to flash my DME with GIAC S2 and don't mind the 5-10HP hit catted downpipes take, if it means I'll never have to worry about messing with the downpipes again.

Boom, how are your CP-E HFC downpipes working for you? Anyone else have the latest DME revision and catted downpipes, with or without a tune?

For those with catless downpipes that have retained the factory secondary cats in the midpipe, did the exhaust smell get considerably worse after installing the catless DPs?

[Yogi335]

Originally Posted by Army335xi

Almost makes you want to leave the stock DP's on and just gut them (not suggesting anyone do this).

...

I was wondering why no one is doing this. TONS of people did this with WRXs. Its cheap, would give performance, and could still pass the visual inspection at the dealer for warranty.

Anyone have any insight.